Trying to send session vals through rack session

test.rb

## My spec
context 'when demo user is logged in' do
  before do
    @user = User.make
    login_as @user
  end

  it 'should be redirected' do
    delete '/user/logout', {}, 'rack.session' => {:someval => 123}
    last_response.status.should == 302
    last_response.headers['Location'].should == 'http://example.org/'
  end
end

## My route
delete '/user/logout' do
  redirect to_homepage unless logged_in?
  puts "-->#{session.inspect}"
  user_session = session.delete(:user)
  redirect to_homepage
end

## Prints out
-->{"session_id"=>"b69aa81c7e262930ebe3d0022bfd7f7c0ad8c0c6d14ac416838bc385a8d2d007", "__FLASH__"=>{}}